Clinical Outcomes Based on Coronary Computed Tomography-Derived Fractional Flow Reserve and Plaque Characterization

Abstract

Background: Coronary computed tomography angiography (CTA) followed by computed tomography angiography-derived fractional flow reserve (FFR_CT) is now commonly used for the management of chronic coronary syndrome (CCS). CTA-verified high-risk plaque (HRP) characteristics have also been reported to be associated with a greater likelihood of adverse cardiac events but have not been used for management decisions.

Objectives: The aim of this study was to evaluate clinical outcomes based on a combination of point-of-care computed tomography angiography-derived fractional flow reserve (POC-FFR_CT) and the presence of HRP in CCS patients initially treated medically or with revascularization based on invasive coronary angiography findings.

Methods: CTA was performed as the initial test in 5,483 patients presenting with CCS between September 2015 and December 2020 followed by invasive coronary angiography and revascularization as necessary. POC-FFR_CT assessment and HRP characterization were obtained subsequently in 745 consecutive patients. We investigated how HRP and POC-FFR_CT, which were not available during the original clinical decision making, correlated with the endpoint defined as a composite of cardiac death, acute coronary syndrome, and a need for unplanned revascularization.

Results: Cardiac events occurred in 20 patients (2.7%) during a median follow-up of 744 days. The event rate was significantly higher in patients with POC-FFR_CT <0.80 compared with POC-FFR_CT ≥0.8 (5.4 vs 0.5 per 100 vessel years; log-rank P < 0.0001) and in patients with HRP compared to those without HRP (3.6 vs 0.8 per 100 vessel years; log-rank P = 0.0001). POC-FFR_CT <0.80 and the presence of HRP were the independent predictors of cardiac events (HR: 16.67; 95% CI: 2.63-105.39; P = 0.002) compared with POC-FFR_CT ≥0.8 and absent HRP. For the vessels with POC-FFR_CT <0.80 and HRP, a significantly higher rate of adverse events was observed in patients who did not undergo revascularization compared with those revascularized (16.4 vs 1.4 per 100 vessel years; log-rank P = 0.006).

Conclusions: POC-FFR_CT <0.80 and the presence of HRP were the independent predictors of cardiac events, and revascularization of HRP lesions with abnormal POC-FFR_CT was associated with a lower event rate.

Keywords: coronary artery disease; coronary revascularization; fractional flow reserve; myocardial ischemia; vulnerable plaques.